This invention relates generally to compressed air delivery systems, and more particularly concerns a compressed air delivery system for delivering clean, dry, compressed air from a source of compressed air to a compressed air appliance.
With the introduction of base coat and clear coat finishes on new automobiles, it has become necessary that paint and body shops be able to duplicate those finishes when repainting damaged automobiles. In order to provide a smooth, blemish free paint job, it is necessary that the compressed air supplied to the pneumatic paint gun be free of particulate, water vapor, and oil vapor and that the pressure at the paint gun remain essentially free of fluctuations.
Various attempts have been undertaken to assure the cleanliness of the air provided to paint guns including refrigerated air dryers and filters of all types ranging from a coalescing filters, desiccant filters, and even toilet paper filters have been used unsuccessfully to control the cleanliness of the air. By installing a number of particulate filters and coalescing filters in series between the compressed air source, it is possible to provide air that is of sufficient cleanliness but under most circumstances the useful life of such filters is relatively short, and they must be replaced as often as daily in some instances. Even with the use of filters, however, unacceptable painting performance may results from fluctuations in the air pressure as a result of several paint guns being operated simultaneously from a single source of compressed air.